Tires have a hidden expiration date that most people never check. Rubber compounds degrade from UV, ozone, and temperature cycling regardless of how many miles you've driven. Old tires can look fine on the surface while the internal structure weakens, increasing blowout risk.
How to read the DOT code
Look at the tire sidewall for a string starting with DOT followed by a series of letters and numbers. The last four digits are the date code:
- First two digits = week of manufacture (01-52)
- Last two digits = year of manufacture
Example: DOT ... 2319 means the tire was made in week 23 of 2019.
The full DOT code is usually only on one side of the tire. If you don't see the last four digits, check the inward-facing sidewall.
When age matters
- 6 years: Most tire manufacturers recommend inspection by a professional after 6 years from the manufacture date, regardless of tread depth or appearance.
- 10 years: The hard limit. Replace any tire over 10 years old even if it looks new. This includes spares sitting in your trunk.
- Spare tire: This is the one most people forget. Your spare might be the original from when the car was built.
Why it matters
Aged rubber loses elasticity and develops micro-cracks internally. At highway speed, heat buildup can cause sudden tread separation — the tire literally comes apart. This is especially dangerous on trailers, RVs, and cars that sit for long periods.
Quick action
Walk out to your car and find the DOT date code on each tire. Check the spare too. If any tire is over 6 years old, plan a replacement regardless of tread depth.
